AIR FLOW
5-3
GENERAL TROUBLESHOOTING GUIDE
Warm compartment
temperatures (continued).
Incomplete defrost
Poor evaporator air flow.
NOTE: To initiate a manual defrost,
see defrost section at front of
Troubleshooting Guide.
1. Faulty door sensor (700 TC/I,
700TF/I only), or faulty reed
switch (all models).
2. Evaporator fan faulty.
3. Evaporator fan blade obstructed.
4. Defrost terminator faulty.
5. Defrost heater faulty.
6. Evaporator thermistor faulty.
NOTE: Evaporator thermistor ter-
minates defrost at 52
o
F (700TC/I,
700TF/I, 700BF/I only).
7. Evaporator sump drain tube
blocked.
8. Drain tube heater faulty (700TC/I,
700TF/I, 700BF/I only).
1. With door shut and reed switches
depressed, check for 115V across P7 &
P5 at control board. If 115V is present,
repair wiring at door sensor or reed
switch, or replace door sensor or reed
switch.
2. With door shut and reed switches
depressed, check for 115V across P9 &
P5 at control board. If no 115V, repair
wiring at evaporator fan or replace
evaporator fan.
3. Clear obstruction.
4. Check wiring to terminator, then check
terminator resistance. If the evaporator
is below 30
o
F, terminator should be
closed. If above 70
o
F, it should be open.
Repair wiring or replace terminator if
faulty.
5. Check for power to heater, then check
resistance of heater. Resistance should
be 20-30 ohms. Repair wiring or replace
evaporator assy.
6. Check wiring and resistance of evapora-
tor thermistor. Resistance should be
approximately 32500 ohms at 32
o
F,
10000 ohms at 77
o
F. Repair wiring or
replace evaporator thermistor.
NOTE: For models 700TC/I, 700TF/I,
700BF/I prior to serial #1201766, remove
evaporator thermistor. This will defrost
evaporator every 6 hours of compressor run
time with a 20 minute dwell.
7. Clear foreign material from drain tube.
8. Check wiring and resistance of drain
tube heater. Resistance should be 1900
ohms. Repair wiring or replace.
Complaint Possible Cause Correction
CAUTION! Low voltage.
DO NOT apply 115 volts.
To Next Page
Loading...
Need help?
General
